which element is a noble gas: Ne, Br, or O
Answer:
_+_
Explanation:
Which of the following applies to a good hypothesis?
Select all that apply
- It explains the data that relates to the specific problem.
- It leads to correct predictions, some of which produce new evidence or experiments.
- It is biased by the experimenter's presuppositions.
- It is formulated based on subjective observations.
- It is formulated based on objective observations
The statements that applies to a good hypothesis are.
It explains the data that relates to the specific problem.It leads to correct predictions, some of which produce new evidence or experiments. It is formulated based on objective observationsGood hypothesis explained.
A good hypothesis ought to give an clarification for the information related to the issue being examined. It ought to too lead to forecasts that can be tried and possibly create modern prove or tests.
A good hypothesis ought to be defined based on objective perceptions, meaning it ought to be grounded in irrefutable and quantifiable information instead of subjective conclusions or inclinations.
It is worth noticing that a hypothesis can be impacted by earlier
information or foundation presumptions, but it ought to still be based on objective perceptions and open to experimental testing and confirmation.
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The predominant intermolecular force in (ch3)2nh is ________. the predominant intermolecular force in (ch3)2nh is ________. london dispersion forces ion-dipole forces hydrogen bonding ionic bonding dipole-dipole forces
Final answer:
The predominant intermolecular force in (CH3)2NH is hydrogen bonding, a strong type of dipole-dipole interaction that occurs due to the presence of highly electronegative nitrogen atoms.
Explanation:
The predominant intermolecular force in (CH3)2NH is hydrogen bonding. This is a special type of dipole-dipole interaction that occurs when hydrogen is bonded to a highly electronegative atom such as nitrogen (N). In (CH3)2NH, the hydrogen atoms attached to the nitrogen can form hydrogen bonds with the nitrogen atoms of adjacent molecules because nitrogen is one of the three most electronegative elements capable of forming hydrogen bonds, along with oxygen (O) and fluorine (F). While London dispersion forces are also present, they are generally weaker than hydrogen bonds and are not the predominant force in this compound.
When seawater evaporates, the concentration of salts increases until _____?
The right answer is the salts precipate out of solution.
There are two types of current evaporites:
* the evaporites of free water, coming from the evaporation of a body of water;
* capillary evaporites resulting from the precipitation of the salts of an intertitle brine in the pores of a sediment.
The formation of evaporites is favored by the arid climate and the confinement of the environment. Nevertheless temperate but very windy coastal areas are also the seat of a strong evaporation.
In the current salt marshes, the confinement of the body of water is accompanied by an intense biological activity: insect larvae, algae, bacteria.
The volume of a gas is 4.00 liters at 293 k and constant pressure. for the volume of the gas to become 3.00 liters, the kelvin temperature must be equal to
Answer:
3.00 * 293 / 4.00
Explanation:
Using Charles's law, which states the direct proportionality between volume and temperature of a gas at constant pressure, the final temperature needed for the gas to reach a volume of 3.00 liters is approximately 219.75 K.
The question is asking about the relationship between the volume and temperature of a gas at constant pressure. This relationship is described by Charles's law, which states that the volume of a gas is directly proportional to its temperature when pressure is held constant. In mathematical terms, V1/T1 = V2/T2, where V1 and T1 are the initial volume and temperature, and V2 and T2 are the final volume and temperature.
Given the initial volume of 4.00 liters and temperature of 293 K, if the volume decreases to 3.00 liters, we can solve for the new temperature using Charles's law:
(4.00 L / 293 K) = (3.00 L / T2)
By cross-multiplying and solving for T2, we get:
T2 = (3.00 L * 293 K) / 4.00 L = 219.75 K
So, for the volume of the gas to become 3.00 liters at constant pressure, the kelvin temperature must be approximately 219.75 K.
What is the ph of a 0.01 m solution of the strong acid hno3 in water?
The pH of a 0.01 M solution of the strong acid [tex]HNO\(_3\)[/tex] in water is 2.
To determine the pH of a strong acid solution, we can use the fact that strong acids completely dissociate in water. This means that for a 0.01 M solution of [tex]HNO\(_3\)[/tex], all of the [tex]HNO\(_3\)[/tex] molecules dissociate into H⁺ ions and [tex]NO\(_3\)\(^-\)[/tex] ions. Therefore, the concentration of H⁺ ions in the solution is equal to the concentration of the [tex]HNO\(_3\)[/tex] solution, which is 0.01 M.
The pH of a solution is defined as the negative logarithm (base 10) of the hydrogen ion concentration [H⁺]:
[tex]\[ \text{pH} = -\log_{10} [\text{H}^+] \][/tex]
Substituting the concentration of H⁺ ions into the equation gives:
[tex]\[ \text{pH} = -\log_{10} (0.01) \] \[ \text{pH} = -\log_{10} (10^{-2}) \] \[ \text{pH} = -(-2) \] \[ \text{pH} = 2 \][/tex]
Thus, the pH of a 0.01 M [tex]HNO\(_3\)[/tex] solution is 2.
When 7.94 g of xylene was added to 132.5 g of cyclohexane, the freezing point of the solution was -4.9oC. What is the molar mass of xylene?
How many grams are in 2.75 moles of KOH? (molar mass=56.11 g/mol)
Answer: C) 154 g
I did the assignment already, it's correct.
51.7ml at 27 Celsius and 90kpa to stp
The number of protons is different for each element and is know as the
What is the mass of 1.71 ✕ 1023 molecules of h2so4?
A gas has a pressure of 0.410 atm and volume of 32 L. At what pressure, would the volume of the gas change to 28 L
A rock is thrown 1.8 meters in the air. Find out how fast it was thrown ?
To calculate the initial velocity of a rock thrown 1.8 meters in the air, we use the vertical motion equation, resulting in an initial velocity of approximately 5.94 m/s.
Explanation:To find out how fast a rock was thrown 1.8 meters in the air, we can use the physics of projectile motion and the equations of motion under the influence of gravity. Given that the height reached by the rock is 1.8 meters, we can use the equation for vertical motion:
h = vi2 / (2g),
where h is the maximum height (1.8 meters), vi is the initial velocity we want to calculate, and g is the acceleration due to gravity (9.8 m/s2). Rearranging the formula to solve for the initial velocity gives us:
vi = sqrt(2gh).
Plugging in the values, we get:
vi = sqrt(2 * 9.8 m/s2 * 1.8 m) = sqrt(35.28) ≈ 5.94 m/s.
Thus, the rock was thrown upwards with an initial velocity of approximately 5.94 m/s.
Using the kinematic equation v^2 = u^2 + 2as, the initial velocity (u) at which the rock was thrown into the air is found to be approximately 5.94 m/s.
Explanation:To calculate the initial velocity at which a rock is thrown into the air, we can use the kinematic equations for projectile motion. Since air resistance is negligible, we'll apply the equation for an object under uniform acceleration due to gravity.
The equation we use is v^2 = u^2 + 2as, where:
v is the final velocity (0 m/s at the peak of the throw).u is the initial velocity (which we are looking to find).a is the acceleration due to gravity (-9.8 m/s^2, the negative sign indicates that gravity is acting downwards).s is the displacement (1.8 meters upwards).Rearranging the equation to solve for the initial velocity (u), we get:
u = √(v^2 - 2as)
Plugging in the known values:
u = √(0^2 - 2*(-9.8 m/s^2)*(1.8 m))
u = √(0 + 35.28)
u = √35.28
u = 5.94 m/s
The rock was thrown with an initial velocity of approximately 5.94 m/s.
A sample of ammonia contains 0.500 mol. What volume at STP would the gas occupy?
The decomposition of dinitrogen tetraoxide into nitrogen gas and oxygen gas is shown by which balanced chemical equation?
Answer: N2o4 - N2 + 202
Explanation:
An explanation based on experimentation and data is a scientific
When methanol, ch3oh, is burned in the presence of oxygen gas, o2, a large amount of heat energy is released. for this reason, it is often used as a fuel in high performance racing cars. the combustion of methanol has the balanced, thermochemical equation ch3oh(g)+32o2(g)â¶co2(g)+2h2o(l)δh=â764 kj how much methanol, in grams, must be burned to produce 541 kj of heat?
[tex]\boxed{{\text{22}}{\text{.69 g}}}[/tex] of methanol must be burned to produce 541 kJ of heat.
Further explanation:
Combustion reaction:
It is the reaction in which the reactant reacts with molecular oxygen to form carbon dioxide and a water molecule. Molecular oxygen acts as the oxidizing agent in these reactions. A large amount of heat is released and therefore combustion reactions are exothermic in nature.
The change in enthalpy that occurs due to the formation of one mole of the compound from its constituent elements is called the standard enthalpy of formation. It is represented by [tex]\Delta {H_{{\text{rxn}}}}[/tex] and its units are kJ/mol.
The combustion of methanol occurs as follows:
[tex]{\text{C}}{{\text{H}}_3}{\text{OH}}+\frac{3}{2}{{\text{O}}_2}\to{\text{C}}{{\text{O}}_2}+2{{\text{H}}_{\text{2}}}{\text{O}}[/tex]
The value of [tex]\Delta {{\text{H}}_{{\text{reaction}}}}[/tex] is -764 kJ/mol. This indicates the heat produced when one mole of methanol is combusted. The negative sign means the heat is released during the process.
The number of moles of methanol [tex]\left( {{\text{C}}{{\text{H}}_3}{\text{OH}}} \right)[/tex] required in the given reaction is calculated as follows:
[tex]\begin{aligned}{\text{Moles of C}}{{\text{H}}_3}{\text{OH}}&=\left({541{\text{ kJ}}} \right)\left( {\frac{{{\text{1 mol}}}}{{764{\text{ kJ}}}}}\right)\\&=0.708{\text{ mol}}\\\end{aligned}[/tex]
The formula to calculate the mass of methanol [tex]\left( {{\text{C}}{{\text{H}}_3}{\text{OH}}} \right)[/tex] is as follows:
[tex]{\text{Mass of C}}{{\text{H}}_3}{\text{OH}}=\left({{\text{Moles of C}}{{\text{H}}_3}{\text{OH}}}\right)\left({{\text{Molar mass of C}}{{\text{H}}_3}{\text{OH}}}\right)[/tex] ...... (1)
The number of moles of [tex]{\text{ C}}{{\text{H}}_3}{\text{OH}}[/tex] is 0.708 mol.
The molar mass of [tex]{\text{ C}}{{\text{H}}_3}{\text{OH}}[/tex] is 32.04 g/mol.
Substitute these values in equation (1).
[tex]\begin{aligned}{\text{Mass of C}}{{\text{H}}_3}{\text{OH}}&=\left({{\text{0}}{\text{.708 mol}}} \right)\left({\frac{{{\text{32}}{\text{.04 g}}}}{{{\text{1 mol}}}}}\right)\\&=22.688{\text{ g}}\\&\approx {\text{22}}{\text{.69 g}}\\\end{aligned}[/tex]
Therefore the mass of methanol burned is 22.69 g.
Learn more:
1. Calculate [tex]\Delta {\text{H}}[/tex] for the reaction using Hess law: https://brainly.com/question/11293201
2. Calculate the hydroxide ion concentration: https://brainly.com/question/11293214
Answer details:
Grade: Senior School
Subject: Chemistry
Chapter: Thermodynamics
Keywords: methanol, CH3OH, combustion, 746 kJ, 541 kJ, mass of CH3OH, molar mass of CH3OH, 22.69 g, moles of CH3OH.
The number of oxygen atoms present in 32.4 g n2o5 is
The number of atoms of any element in the given chemical formula is the number that is written on the food of the symbol of that element. The total number of atoms of oxygen in given molecule is 9.033 ×10²³.
What is atom?Atom is the smallest particle of any matter. Atom combines to form element and element combine to form molecule or compound. Atom can be further divided into electron, protons and neutrons.
1 molecule of given molecule contain 5 atoms of oxygen
Molar mass of N₂O₅= 108.01 g/mol
given mass of N₂O₅=32.4 g
Number of moles of N₂O₅= given mass÷molar mass =0.3mol
Number of atoms= 0.3 ×6.022×10²³
Number of atoms=1.8066 ×10²³
total number of atoms=5×1.8066 ×10²³
=9.033 ×10²³atoms of oxygen
Thus the total number of atoms of oxygen in given molecule is 9.033 ×10²³.
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Final answer:
approximately 9.033 x 10^23 oxygen atoms.
Explanation:
Calculating the Number of Oxygen Atoms in 32.4 g of N2O5
To determine the number of oxygen atoms in 32.4 g of N2O5, we first need to understand the concept of moles and how it relates to the mass of a substance. N2O5 has a molecular mass of 108.02 amu. This means one mole of N2O5 weighs 108.02 grams and contains Avogadro's number of molecules. Using the equation for calculating moles, where n is the number of moles, m is the mass of the substance in grams, and M is the molar mass of the substance in g/mol, the formula is:
n = m / M
Substituting the given values:
n = 32.4 g / 108.02 g/mol ≈ 0.3 moles of N2O5
Since each molecule of N2O5 contains 5 oxygen atoms, we multiply the number of moles of N2O5 by 5 and then by Avogadro's number (6.022 x 1023) to get the total number of oxygen atoms:
Total oxygen atoms = 0.3 moles x 5 x 6.022 x 1023 ≈ 9.033 x 1023 oxygen atoms
What type of reaction is
Na2S (I) + CdNO3 (I) => CdS (s) + 2NaNO3 (I)
A. Double-Displacement
B. Single-Displacement
C. Decomposition
D. Synthesis
Answer:
The correct answer is A. Double-Displacement
Explanation:
A double displacement reaction is that two elements found in different compounds exchange positions, forming two new compounds. These chemical reactions do not present changes in the number of oxidation or relative load of the element. Generally the exchange occurs between reagents that are ionic compounds in solution, where the anions and cations of the compounds are exchanged.
Double displacement reactions follow the following general chemical equation:
AB + CD --- AD + CB
The initial compounds AB and CD react by exchanging "their partners" and thus form two new compounds: AD and CB. This reaction takes place if and only if A and D are more similar than A and C, or if CB links are more stable than those of CD. Since the reaction is a simple ion exchange, none of these gain or lose electrons, as mentioned above. Thus, if A is a +1 charge cation in compound AB, it will have the same +1 charge in compound AD.
The solvent of the double displacement reactions is almost always water and the reagents and products are usually ionic compounds, although they can also be acids or bases.
On the other hand, a precipitation reaction occurs when two aqueous ionic compounds form a new ionic compound that is not soluble in water. It is an example of double displacement reactions. In most precipitation reactions, one salt is soluble and the other precipitates. The insoluble compound that results is called precipitate. The solvent and soluble reaction compounds are called the supernatant. This is the type of reaction that happens in this case. In this case the insoluble compound is cadmium sulfide CdS.
Calculate the mass of chromium found in the 2.50 g sample of stainless steel
To find the mass of 0.560 moles of chromium, multiply the number of moles by the molar mass of chromium (51.996 g/mol), resulting in 29.11816 grams.
Explanation:
To calculate the mass of chromium found in a 2.50 g sample of stainless steel, we need to know the percentage composition of chromium in the alloy. However, the question provides data for 0.560 moles of chromium and not the composition of the stainless steel sample. To find the mass of 0.560 moles of chromium, we use the molar mass of chromium.
Steps to Calculate Mass of Chromium
Determine the molar mass of chromium from the periodic table, which is approximately 51.996 g/mol.Multiply the number of moles of chromium (0.560 moles) by its molar mass.The resultant product gives the mass of 0.560 moles of chromium.Performing this calculation: 0.560 moles × 51.996 g/mol = 29.11816 grams of chromium.
what is part of the first stage in the process of technological design
Answer:
Researching information
Explanation: Edge 2020
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Identifying the problem is the first stage in the process of technological design.
What do you mean by technological design?Technological design is a distinctive process with a number of defining characteristics: It is purposeful; it is based on certain requirements; it is iterative; it is creative; and it is systematic.
The four steps in the technological design process are:
Identify the problem Design a solution or product Implement the design Evaluate the product/solution.Hence, identifying the problem is the first stage in the process of technological design.
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Sulfuric acid reacts with aluminum hydroxide by double replacement. if 34 g of sulfuric acid react with 33 g of aluminum hydroxide, identify the limiting reactant.
To determine the limiting reactant between sulfuric acid and aluminum hydroxide, calculate the moles of each reactant using their molar masses. Comparisons based on the stoichiometric ratios from the balanced chemical equation reveal that sulfuric acid is the limiting reactant.
Explanation:To identify the limiting reactant when 34 g of sulfuric acid reacts with 33 g of aluminum hydroxide, we need to calculate the moles of each reactant based on their molar masses. The balanced chemical equation for the reaction between sulfuric acid (H₂SO₄) and aluminum hydroxide (Al(OH)₃) is:
3 H₂SO₄(aq) + 2 Al(OH)₃(s) → Al₂(SO₄)₃(aq) + 6 H₂O(l)
First, determine the molar mass of H₂SO₄, which is approximately 98 g/mol, and Al(OH)₃, which is approximately 78 g/mol. Then, calculate the moles of each reactant:
Moles of H₂SO₄ = 34 g / 98 g/mol = 0.347 molesMoles of Al(OH)₃ = 33 g / 78 g/mol = 0.423 molesThe balanced equation shows that 3 moles of H₂SO₄ react with 2 moles of Al(OH)₃. We then set up ratios to see which reactant is limiting:
0.347 moles H₂SO₄ × (2 moles Al(OH)₃ / 3 moles H₂SO₄) = 0.231 moles Al(OH)₃ required0.423 moles Al(OH)₃ × (3 moles H₂SO₄ / 2 moles Al(OH)₃) = 0.635 moles H₂SO₄ requiredSince we only have 0.347 moles of H₂SO₄ but require 0.635 moles to react with all the available Al(OH)₃, sulfuric acid is the limiting reactant.
Find number atoms in each element?
Explanation:
Formula of gypsum is [tex]CaSO_{4}.2H_{2}O[/tex]. Therefore, total number of atoms of each element present in gypsum are as follows.Number of Ca atom = 1
Number of S atom = 1
Number of O atom = 6
Number of H atom = 2
Formula of cellulose is [tex]C_{6}H_{7}O_{2}(OH)_{3}[/tex]. Therefore, total number of atoms of each element present in 2 molecules of cellulose are as follows.Number of Ca atom = 2 × 6 = 12
Number of H atom = 2 × 10 = 20
Number of O atom = 2 × 5 = 10
Formula of antiperspirant is [tex]Al_{2}Cl(OH)_{5}[/tex]. Therefore, total number of atoms of each element present antipersiperant are as follows.Number of Al atom = 2
Number of Cl atom = 1
Number of O atom = 5
Number of H atom = 5
which of the following groups contain 3 elements with stable electron configuration
a. xenon, neon, boron
b. calcium, krypton, argon c. helium, xenon, carbon d. argon, neon, xenon
Option d, which includes argon, neon, and xenon, contains three elements with stable electron configurations as they are all noble gases with full valence shells.
The student's question pertains to the electron configuration of elements, specifically identifying a group of elements that all have stable electron configurations. A stable electron configuration typically means having a full valence shell of electrons, which is characteristic of the noble gases. Noble gases include helium, neon, argon, krypton, xenon, and radon, and they are known for being chemically inert, or nonreactive, due to their complete electron shells. The correct answer to the question is option d. argon, neon, xenon, as all three of these elements are noble gases and therefore have a stable electron configuration.
Which of these choices is an indirect cost of using coal?
A. Cost to transport coal
B. Cost of maintaining power plants
C. Cost to mine coal
D. Cost of pollution from burning coal
Answer:
D. Cost of pollution from burning coal
Explanation:
Energy resources can be classified into two categories: renewable and non-renewable.
Renewable resources are those that can be replenished within a short time. This includes, wind energy, solar, hydrothermal etc
Non-renewable resources in contrast, are finite and are in limited supply. This includes, fossil fuels like coal, oil and natural gas as well as nuclear energy.
Coal is a fossil fuel which also the most common source of energy. However, it pollutes the environment by emitting carbon dioxide which is greenhouse gas.
In an ecosystem ,cost of pollution from burning coal is an indirect cost of using coal.
What is an ecosystem?Ecosystem is defined as a system which consists of all living organisms and the physical components with which the living beings interact. The abiotic and biotic components are linked to each other through nutrient cycles and flow of energy.
Energy enters the system through the process of photosynthesis .Animals play an important role in transfer of energy as they feed on each other.As a result of this transfer of matter and energy takes place through the system .Living organisms also influence the quantity of biomass present.By decomposition of dead plants and animals by microbes nutrients are released back in to the soil.
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Consider the reaction between 50.0 ml liquid methanol, ch3oh (density 0.850 g/ml), and 22.8 l o2 at 27c and a pressure of 2.00 atm. the products of the reaction are co2(g) and h2o(g). calculate the number of moles of h2o formed if the reaction goes to completion.
To calculate the number of moles of H2O formed, determine the moles of CH3OH involved in the reaction, convert the volume of CH3OH to mass using its density, convert the mass of CH3OH to moles using its molar mass, and use the balanced chemical equation to determine the stoichiometry between CH3OH and H2O.
Explanation:To calculate the number of moles of H2O formed, we first need to determine the number of moles of CH3OH and O2 involved in the reaction.
1. Convert the volume of CH3OH to mass using its density:
Mass of CH3OH = Volume of CH3OH x Density = 50.0 mL x 0.850 g/mL = 42.5 g
2. Convert the mass of CH3OH to moles using its molar mass:
Moles of CH3OH = Mass of CH3OH / Molar mass of CH3OH = 42.5 g / 32.04 g/mol = 1.327 mol
3. Use the balanced chemical equation to determine the stoichiometry between CH3OH and H2O:
1 mol of CH3OH produces 2 mol of H2O
Therefore, 1.327 mol of CH3OH will produce 2 x 1.327 = 2.654 mol of H2O
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Why is radon gas dangerous at high levels?
The radon is the decay byproduct of radium which emits alpha rays to convert into the lead or polonium. The alpha particles have less penetration inside the cell than the beta particle or gamma rays and have the more dangerous effect than these other days. In the environment, the high presence of radon enters into the lungs through breathing and start to decay. In their decay, it emits alpha rays, which acts as the carcinogenic agent in the body.
HELP. Check all answers that apply.
Copper oxide is a(n):
atom.
molecule.
subatomic particle.
element.
compound.
What is the energy of an object in motion
It's kinetic energy :)
A hydrate of CuSO4 has a mass of 12.98 g before heating. After heating, the mass of the anhydrous compound is found to be 9.70 g.
Explain how you would determine the formula of the hydrate and then write out the full name of the hydrate.
The solution follows as;
Given:
CuSO4 – 9.70 (weight)
Water / H2O – 12.98 – 9.70 = 3.28 (weight)
Molecular weight of CuSO4 – 160
Molecular weight of H2O – 18
To solve;
= weight of CuSO4 x MW of CuSO4
= 970 / 160
= 328/x*18
= 6x = 18
= x – 3
= CuSO4*3H2O